Hello my friend,
hmmm RS232 is actually a serial standard not a port standard... there are many 9PIN ports - the common one we use for joysticks is actually a DeB9 Plug -
These connectors are predominately digital interfaces with a couple of POT's (potentiometers) used for X and Y.
The Playstation controller is more like a serial device, a lot like the SNES adapters - it wouldn't take much to arbitrate a PS1 or 2 controller with a Serial bus, however you would need to write some software to use it - a Serial device wouldn't work with most games, or any that are WHDLoad since it wont have a driver or looking at a port for its input.
Have you a link to these items my friend, I can have a look and offer you a better opinion if these are SERIAL or DeB9 digital compatible.